Effects of Stress-Strain Data Synchronisation Errors on the Determination of Young’s Modulus of Hard and Soft Materials in Material Testing Machines

Abstract

In this paper, the effects of stress-strain data synchronisation errors on Young's modulus of hard and soft materials in typical material testing machines are described. Seven materials, three Cu-Cr-Zr alloys and four polymers, are tested in two machines conceived for the measurement of the mechanical properties of hard and soft materials. In both machines, the synchronisation of stress and strain signals are guaranteed by the machine's internal signal processing system. By performing known temporal shifts with respect to each other, the Young's modulus is calculated. In this way, the variation of Young's modulus as a function of the temporal shift can be determined and the sensitivity coefficients, to be used in the uncertainty evaluation, derived.